I don't really buy this. There's simply no way that messing with the NO pathway can prevent DNA degradation resulting from radiation exposure. I'm not familiar with irradiation units and how they correlate to DNA damage, but all amounts are harmful to the molecule. Ionizing radiation damage can be fixed via repair pathways, but it's simply a function of probability as to when this machinery fails in a critical location.
The paper might be interesting to read, though, especially if it got cited. As always, news articles tend to inflate claims and miss the point entirely.